The disappearance of a patient on Shutter Island brings U.S. Marshal Teddy Daniels and his new partner to Ashecliffe Hospital, a fortress-like insane asylum located on a remote island. The woman appears to have vanished from a locked room, and there are hints of terrible things going on within the hospital. As the investigation deepens, Teddy realizes he will have to confront his own dark fears if he hopes to make it off the island alive.